Scanning mirrors operated in synchronism with modulated light sources have been used for generating images that are projected onto viewing screens. Typically, the scanning mirrors are incrementally inclined in synchronism with the output of the modulated light sources for writing raster traced images onto the viewing screens in accordance with video signals. Two-dimensional scanning mirror systems (e.g., mirrors rotatable about two orthogonal axes) can be used in combination with synchronized light sources (usually lasers) for generating two-dimensional images. Alternatively, one-dimensional scanning mirror systems (e.g., mirrors rotatable about a single axis) can be used in combination with synchronized one-dimensional image generators (e.g., linear arrays) for generating two-dimensional images.
Reluctance based on perceived safety concerns and image quality persists to projecting images written by laser beams directly into viewers' eyes as required for forming virtual images with near eye displays. Laser light is also prone to speckle, which can degrade the images. However, scanning mirrors have been used in conjunction with linear arrays of light-emitting diodes for generating virtual raster scan images that are projected directly into viewers' eyes. For example, a scanning mirror can be located in a viewer's line of sight and oriented for redirecting the generated beams, nominally through right angles, on paths into the viewer's eyes. These near eye displays with in-line scanning mirrors include large focusing optics for filling the mirrors and tend to be quite thick and otherwise cumbersome for mounting on viewers' heads as eyeglasses, headbands, or helmet attachments.